How Much Does A Thermostat Replacement Cost in the UK?

A car thermostat is a device that regulates the temperature and flow of a car's engine coolant. It is located between the engine and the radiator. The thermostat is closed when the engine is cold and opens when the engine warms up to increase cooling capacity. If the thermostat becomes damaged or fails to open, it can cause the engine to overheat, which can lead to serious engine damage.

How much does it cost to replace a car thermostat?

The average cost of replacing a car thermostat is £150, with prices ranging from £95 and £215. If the faulty thermostat has caused overheating, it can result in damage to other parts of the engine such as the head gasket which is a further, more costlier repair. The exact price of the thermostat replacement depends largely on your car and the parts recommended by the manufacturer.

Your location can also be a key factor in determining the price of a car thermostat replacement. For example, average hourly labour rates and demand in cities like London is around £50-£100 while in towns with lower demand, the labour rates can range from £35-£50. The type of mechanic, for example, a mobile mechanic vs a dealership garage technician can also affect the total cost of a car thermostat replacement.

Average cost of a thermostat replacement by location

To avoid having car owners overpaying and get a fair price for a thermostat replacement, we use real-time data of thousands of car makes and model data, local labour prices for thermostat repairs and replacements and part prices to provide an instant fair quote. Simply enter your vehicle registration number and postcode to get an instant price for a car thermostat replacement for your car.

Average cost of a thermostat replacement by manufacturer

Signs your car thermostat needs a replacement

• Engine overheating
• Engine overcooling
• Coolant leaking
• Heater malfunctioning
• Fluctuating temperature gauge
• Check Engine Light or Temperature warning light on
  
  

Engine overheating

Overheating can indicate a problem with the thermostat, but it can also be caused by other issues such as a coolant leak, a clogged radiator, or a failed water pump. When a thermostat is ‘stuck’ closed, coolant cannot flow causing the engine to overheat which keeps the temperature higher than it should be. It’s best to get this checked by a mechanic as soon as possible as continuing to drive will cause further damage to the vehicle.

Engine overcooling

The thermostat can also fail and become stuck open. This will result in an engine that runs cool or is slow to get up to temperature. The cabin heater performance is usually poor as well as increased fuel consumption

Check engine or temperature warning light

If the check engine light is accompanied by symptoms such as the engine overheating, it is possible that the thermostat is the root of the problem. The temperature warning light on the dashboard could also light up if the thermostat has failed.

Frequently asked questions about thermostat replacement cost

Is a car thermostat expensive?

While thermostats themselves are usually not expensive, the labour to replace them can add to the cost since it takes between 1 and 2 hours to replace them, depending on the vehicle's make and model.

Why is my car overheating but it has coolant in it?

One reason your car might be overheating is that the water pump is not circulating the coolant properly. The water pump is driven either by an auxiliary belt or timing belt connected to the engine's crankshaft, and if this belt is loose or broken, the water pump will not be able to do its job. It could also overheat due to the thermostat malfunctioning and not being able to regulate the engine temperature. Another possibility is that the radiator is clogged and is not able to dissipate heat properly.

Can I drive my car with a broken thermostat?

Ideally, no. Driving with a bad thermostat can cause your engine to overheat. This can potentially lead to engine damage which is far worse and more costly to fix than getting the thermostat fixed.

Can a bad thermostat cause a blown head gasket?

Yes, a bad thermostat could potentially cause a blown head gasket. If the thermostat is stuck and cannot regulate the temperature of the engine, it could cause the engine to overheat. An overheated engine is one of the main causes of a blown head gasket.

How long does a car thermostat replacement take?

On average a car thermostat replacement will usually take around 1 hour, but can take anywhere from under 1 to over 2 hours. In some cases, it can take longer if it has resulted in a blown head gasket which will also need replacing. The time that the job takes will depend on a range of factors. For example, your vehicle's make and model, year, as well as other factors. Select your car at the top of this page for information on job time and cost for your vehicle through ClickMechanic.

Can I carry out a car thermostat replacement myself?

Unless you are a qualified mechanic with the required skills, training and equipment to do the job, we strongly recommend a car thermostat replacement is only carried out by a professional mechanic. ClickMechanic can help get you a vetted and local mechanic to carry out the work. Just enter your postcode and your car's registration number at the top of this page and select the work needed to get an instant fixed price upfront.

What else could be the problem if my car thermostat isn’t broken?

• Coolant level - if coolant levels are not at the required level then it can cause overheating or overcooling issues. Low coolant levels could also be a result of coolant leakage
• Car radiator - a faulty radiator can result in overheating issues
• Water pump failure - a faulty water pump will restrict the proper flow of coolant within the engine which will often lead to overheating
• Blown head gasket - a blown head gasket can result in the mixing of combustion gases, coolant and engine oil, leading to overheating and in severe cases engine damage
• Electrical issues - damaged sensors or wiring can also cause cooling issues

What happens during a car thermostat replacement?

During a car thermostat replacement job, the technician will typically follow these steps:

• Mechanic will read the ECU to see if there are any related fault codes.
• Mechanic will inspect the thermostat and the cooling system.
• If necessary, the mechanic will replace the thermostat.
• Mechanic will close the cooling system and refill the system with engine coolant.
• Mechanic will run the engine and, if necessary, test drive the car.
• Mechanic will make any adjustments if necessary.